sexta-feira, 29 de junho de 2012

Media Server XMPP component

The main module from the Media Server is its XMPP component, it has several responsibilities, including the authentication process.

The authentication process that will be used is based on the XEP-0070, to illustrate how it would work, here is a sequence diagram:

As described on XEP-0070, the Media Server will provide two types of HTTP authentication, Basic and Digest, both requests user's login and password as authentication mechanism, in this way, the Media Server has to have a mechanism where it will verify the passed password.

The authentication response and authorization request are already implemented, the next steps are implement the verify password mechanism and request confirmation process.

edit: changed the sequence diagram after discussed some points with Kev.

quinta-feira, 14 de junho de 2012

GSoC 2012 - Everything seems to be flowing well

Last week I've faced some problems due to URL confusion, but, it was easily fixed changing a little the approach that I was taking in the resources implementation.

In resume, this is what was implemented this week:
  • All Media Server API methods without any kind of authentication. In this way, the whole defined actions (upload, update, download and delete) are working (in a very naive way, but still...);
  • Simple tests just to verify if everything is working in a minimum condition;
  • Documentation improvement at buddycloud's wiki;
  • A test suite, where we can run all test cases developed so far.
I also started the implementation of the other main Media Server feature, the XMPP component. It will be responsible to communicate with the buddycloud server and ask about users permissions based on pub-sub. I'm expecting a lot of tricky coding challenges in this phase :-D

Other interesting information is about the authentication process that I'm planning to use for the Media Server:
It is a well defined XEP about how to authenticate HTTP requests via XMPP. Denis, the other buddycloud's GSoC student, has started a very interesting discussion about how would work the HTTP Pub-Sub API and the Media Server together using the XEP cited above:!topic/buddycloud-dev/5KOmqMKXEko

I'm planning to end the XMPP component in the next couple of weeks with the functionality of handling media for public buddycloud channels, this will allow a first 0.0.1 version deploy and further real tests. As usual, what I expect is to experience a lot of bugs and crashes, but not in everything (I hope so...).

sábado, 9 de junho de 2012

GSoC 2012 - Some specification changes

During the last two weeks, we decide to do some changes at the URLs definitions and the stored metadata of each media.

Now, the URLs are:

POST /media/<entityId>

PUT, DELETE, GET /media/<entityId>/<mediaId>

POST, PUT, DELETE, GET /media/<entityId>/avatar

Also we defined two query parameters, maxheight and maxwidth, in this way, if the client sends a request like

GET /media/

The returned media is a preview of " aksdh10201d " with dimensions that not exceed 100x100. It is assumed that the client will ask for previews of "thumbnailing" media, like images and videos.

Since /media/<entityId>/<mediaId> and /media/<entityId>/avatar can be confused by Restlet's router, I'm facing some problems due to that, I'm trying to figure out a solution that doesn't involve changing those defined URL templates.

Other significant change occurred at POST media request, now, the client should provide a multipart/form-data with 6 parameters:

  • uploadtoken: related to authentication process;
  • filename: the real name of the file (including its extension);
  • title: a title for the media (optional);
  • description: media's description;
  • author: the user that is uploading this file;
  • binaryFile: the file content.
The server response is a JSON representation of the uploaded media metadata:

   "title":"Test Image",
   "description":"My Test Image",

Next week, I'm planning to fix the URL confusion issue, and develop the first XMPP functionalities, like upload/download media from public channels.